C $Header: /u/gcmpack/MITgcm/pkg/cal/cal_getmonthsrec.F,v 1.3 2012/04/13 18:03:11 jmc Exp $ C $Name: $ #include "CAL_OPTIONS.h" subroutine CAL_GETMONTHSREC( O fac, first, changed, O count0, count1, I mytime, myiter, mythid & ) c ================================================================== c SUBROUTINE cal_GetMonthsRec c ================================================================== c c o Given the current model time or iteration number this routine c returns the corrresponding months that will have to be used in c order to interpolate monthly mean fields. The routine derives c from *exf_GetMonthsRec* of the external forcing package. c c started: Christian Eckert eckert@mit.edu 21-Apr-2000 c - ported from the external forcing package and slightly c modified (10 --> nmonthyear-2, 12 --> nmonthyear). c c changed: Patrick Heimbach heimbach@mit.edu 15-Jun-2000 c - fixed bug for count1 = nmonthyear c c ================================================================== c SUBROUTINE cal_GetMonthsRec c ================================================================== implicit none c == global variables == #include "cal.h" c == routine arguments == _RL fac logical first logical changed integer count0 integer count1 _RL mytime integer myiter integer mythid c == local variables == integer currentdate(4) integer midtime(4) integer middate(4) integer tempDate(4) integer middate0_1, middate0_2 integer middate0(4) integer middate1_1, middate1_2 integer middate1(4) integer prevdate(4) integer shifttime(4) integer startofmonth_1, startofmonth_2 integer endofmonth_1, endofmonth_2 integer startofmonth(4) integer endofmonth(4) integer difftime(4) integer present integer previous integer next integer prevcount integer modelsteptime(4) _RL currentsecs _RL prevsecs _RL midsecs_np _RL diffsecs _RL midsecs c == end of interface == ce --> Include a check whether the right calendar is used. shifttime(1) = 1 shifttime(2) = 0 shifttime(3) = 0 shifttime(4) = -1 call CAL_TIMEINTERVAL( -modelstep, 'secs', modelsteptime, & mythid ) c Determine the current date and the current month. call CAL_GETDATE( myiter, mytime, currentdate, mythid ) present = mod(currentdate(1)/100,100) startofmonth_1 = (currentdate(1)/100)*100 + 1 startofmonth_2 = 0 call CAL_FULLDATE( startofmonth_1, startofmonth_2, & startofmonth, mythid ) endofmonth_1 = (currentdate(1)/100)*100 + & ndaymonth(present,currentdate(3)) endofmonth_2 = 235959 call CAL_FULLDATE( endofmonth_1, endofmonth_2, & endofmonth, mythid ) c Determine middle of current month. currentsecs = float( & (mod(currentdate(1),100)-1)*secondsperday + & currentdate(2)/10000*secondsperhour + & mod(currentdate(2)/100,100)*secondsperminute + & mod(currentdate(2),100) & ) midsecs = float(ndaymonth(present,currentdate(3))* & secondsperday/2) call CAL_TIMEINTERVAL( midsecs, 'secs', midtime, mythid ) call CAL_ADDTIME( startofmonth, midtime, middate, mythid ) call CAL_ADDTIME( currentdate, modelsteptime, prevdate, mythid ) prevsecs = float( & (mod(prevdate(1),100)-1)*secondsperday + & prevdate(2)/10000*secondsperhour + & mod(prevdate(2)/100,100)*secondsperminute + & mod(prevdate(2),100) & ) c-- Set switches for reading new records. first = ((mytime - modelstart) .lt. 0.5*modelstep) if ( first ) then changed = .false. endif if ( currentsecs .lt. midsecs ) then count0 = mod(present+nmonthyear-2,nmonthyear)+1 prevcount = count0 shifttime(1) = -shifttime(1) call CAL_ADDTIME( startofmonth, shifttime, middate0, mythid ) middate0_1 = (middate0(1)/100)*100 + 1 middate0_2 = 0 call CAL_FULLDATE( middate0_1, middate0_2, tempDate, & mythid ) previous = mod(tempDate(1)/100,100) midsecs_np = float(ndaymonth(previous,tempDate(3))* & secondsperday/2) call CAL_TIMEINTERVAL( midsecs_np, 'secs', midtime, mythid ) call CAL_ADDTIME( tempDate, midtime, middate0, mythid ) count1 = present middate1(1) = middate(1) middate1(2) = middate(2) middate1(3) = middate(3) middate1(4) = middate(4) else count0 = present if ( prevsecs .lt. midsecs ) then prevcount = mod(present+nmonthyear-2,nmonthyear)+1 else prevcount = present endif middate0(1) = middate(1) middate0(2) = middate(2) middate0(3) = middate(3) middate0(4) = middate(4) count1 = mod(present+1,nmonthyear) if ( count1 .EQ. 0 ) count1 = nmonthyear call CAL_ADDTIME( endofmonth, shifttime, middate1, mythid ) middate1_1 = (middate1(1)/100)*100 + 1 middate1_2 = 0 call CAL_FULLDATE( middate1_1, middate1_2, tempDate, & mythid ) next = mod(tempDate(1)/100,100) midsecs_np = float(ndaymonth(next,tempDate(3))* & secondsperday/2) call CAL_TIMEINTERVAL( midsecs_np, 'secs', midtime, mythid ) call CAL_ADDTIME( tempDate, midtime, middate1, mythid ) endif call CAL_SUBDATES( middate1, middate0, difftime, mythid ) call CAL_TOSECONDS( difftime, diffsecs, mythid ) c Set counters, switches, and the linear interpolation factor. if ( (.not. first) .and. (prevcount .ne. count0) ) then changed = .true. else changed = .false. endif if ( currentsecs .lt. midsecs ) then fac = (midsecs - currentsecs)/diffsecs else fac = (2.*midsecs + midsecs_np - currentsecs)/ & diffsecs endif return end